【作者】 刘荣芳；

【导师】 温长顺； 陈鸿汉；

【作者基本信息】 中国地质大学（北京） ， 构造地质学， 2007， 博士

【摘要】 本文在扶余油田水文地质、工程地质和环境地质调查基础上对研究区的地下水污染机理和污染途径进行研究分析。研究区在扶余油田西南部，以八家子为研究中心，东西宽3.7km，南北长6.8km，总面积为25.1km²，占油田总面积的1／4。 研究区石油储存在白垩系的泉头组四段，新构造活动使得白垩系顶部、古近系和新近系缺失，第四系直接覆盖在泉头组之上。地下水主要存在于第四系中，分下、中更新统承压水和中、上更新统微承压水。两个含水系统分别采样，上部地下水化学特征主要为HCO₃-NaCa型，个别出现HCO₃Cl-Na型水，以Cl^-、石油类和碘三项严重污染为特征，其次，是SO₄^2-、NO₂^--N、总硬度。下部含水层化学特征HCO₃-Ca型水，与区域地下水的HCO₃-NaCa型有所不同。重度污染项目主要为石油类、碘和NO₃^--N三项，其次为Cl^-。与上段地下水相比较，从污染项目及其污染程度所占比例，下段地下水污染项目相对少，污染程度所占比例低，但石油类下段较上段污染严重。通过与背景值对照以及与地下水Ⅲ级标准对比，分析出两段地下水中主要污染物是石油类和氮类。 结合油田区特殊的地质坏境，发现污染物对地下水的污染途径主要有三种形式：渗透污染、穿透污染和事故性污染。该油田区石油类渗透污染物的主要来源是渗坑和土油池及落地油。穿透污染是污染物沿着裂隙到达含水层从而污染地下水的方式。裂隙主要由强烈开采地下水产生不均匀地面沉降引起、地质构造活动引发和冻胀地裂缝。重点分析因基底发生新构造活动诱发的地裂缝作为穿透污染的重要通道对地下水水质的影响。构造裂缝又分为地表构造地裂缝，将污染物从地表通过地沟、地裂带到含水层；还有一种是地下隐伏构造裂隙或断裂，原油通过地下隐伏构造裂隙或断裂上窜至含水层。事故性污染在研究区由于设备的老化及检修的不及时也经常造成地下水的污染。更多还原

【Abstract】 Based on hydrology and environmental geology works, the dissertation mainly discussed pollution ways and mechanism. The study site is in southwest of the oilfield, 3.7km wide and 6.8km long, totally is 25.1km², one quarter of the whole oilfield, and Bajiazi village is its center.Quantou formation of Cretaceous was oil reservoir, for the continually surging lift activities from Cretaceous to Quaternary, neotectonic activities denuded the upper of the Cretaceous, the whole Paleogene and Neogene, which made the Quaternary overlaid oil layers directly. Groundwater mainly was in Quaternary, lower-mid Pleistocene porous tiny pressure aquifer and mid-upper Pleistocene porous pressure aquifer. Chemical property of the upper aquifer mainly was HCO₃-NaCa, except HCO₃CL-Na. In this aquifer, chloride, oil and iodide were main polluting detection index. In the next place were SO₄^2-, NO₂^- -N and total hardness. The lower aquifer was HCO₃-Ca chemical property, different from HCO₃-NaCa of areal groundwater. Heavy contaminant indexes were oil, iodide and NO₃^- -N, chloride was less. Compared with indexes of the upper aquifer, numbers of contaminant indexes were less and polluted to less extent except for oil. In both aquifers, oil and nitride were main pollutants.Combined with special geological environment and human activities in the oilfield, we mainly found three ways by which pollutant to groundwater: infiltrating pollution, penetrating pollution and accidental pollution. Infiltrating pollution sources came from Seepage Pit, earthy oil ponds and spilled oil. Ways of pollutants contaminating groundwater by fractures were penetrating pollution. Two types of geofractures which affected the groundwater most usually were sorted on the base of factors inducing their formation, one was subsidence geofractures consisted on extracting extensive groundwater and inducing uneven depression, the other was structural geofracture based on geological structure activities. Structural geofractures in study site included surface fractures and buried faults. On the ground, all kind of pollutants arrived in aquifer by channels and geofractures, at the same time, crude oil moved into Quaternary aquifer along the buried active fractures and fissures. Accidental pollution usually caused by old producing oil facilites leakage and it polluted groundwater heavily when workers were reckless of examining and repairing oil pipes on time.更多还原